The NEI Central Transgenic Animal Facility is a research support facility for all NEI intramural researchers requiring the use of transgenic mice in their research programs. We are currently providing transgenic animal support to researchers from six laboratories in the NEI (LI, LMDB, LMOD, LRCMB, OGCSB, OSD); in our program, there are currently 200 DNA constructs which are at various stages of completion. NEI researchers, using molecular biology techniques to study the eye, submit DNA constructs to our section for production of transgenic mice. We create transgenic mice by standard procedures, then biopsy and perform DNA analysis on the mice which are born from these procedures to identify transgene positive mice. At the researchers' request, we mate positive transgenic mice, wean litters, biopsy and analyze DNA from successive generations of transgenic mice, provide the transgenic animals to researchers for use in their experiments, and cryopreserve and bank embryos from important mouse lines (both transgenic and naturally occurring) for long term storage. This year we have: * generated 64 transgenic founder mice from 28 DNA constructs; * set up 321 matings of transgenic mice; * weaned, tagged and tail biopsied 3,434 mice; * isolated DNA from 3,901 samples; performed 5,353 DNA analysis; * frozen 247 embryos to preserve 1 mouse line. Since the program began in 1991 we have: * generated 984 transgenic founder mice from 200 DNA constructs; * set up 2,341 matings of transgenic mice; * weaned, tagged and tail biopsied 24,935 mice; * isolated DNA from 24,985 samples; performed 28,787 DNA analysis; * frozen 5,797 embryos to preserve 20 mouse lines.